Vacuum tube electronic switch



B. CONLEY VACUUM TUBE ELECTRONIC SWITCH Aug. 3, 1948.

2 Sheets-Sheet 1 Filed April 11. 1945 Aug. 3, 1948. B. CONLEY VACUUM TUBE ELECTRONIC SWITCH Filed April 11,1945 2 Sheets-Sheet 2 [=MVX. [no

Patented Aug. 3, 1948 VACUUM TUBE ELECTRONIC svvrrcn Burns Conley, United States Army, Wevaco, W. Va.

Application April 1.1, 1945, said No. 537,823 4 Claims. (01. 2511-275) (Granted under the act of March 3, 1883, as

The invention described herein may be manufactured and used by or for the Governmentfor governmental purposes, without the payment to me of any royalt thereon.

This invention relates to electronic devices and more particularly to a vacuum tube electronic switch having a movable grid.

Heretofore, the small output currents of devices such as photo-electric cells and thermocouples had to be amplified before such currents could be applied to anything but a sensitive meter.

It is an object of this invention to provide an electronic switch or relay capable of producing electrical impulses of a much greater magnitude than the electrical impulses actuating the device. It is another object of this invention to provide a thermionic device for use in connection with electrical apparatus of the type that is capable of producing only an eXtremeIy weak current, such as photocells, thermocouples, etc.

According to my invention a thermionic switch isprovided with a. cathode, a plurality of anodes positioned to receive a flow of electrons from said cathode, a control electrode mounted for rotation relative to the cathode and arranged to control the electron fiow from the cathode to the respective anodes, and a DArsonval type of meter having an armature upon which the control grid is mounted, the entire thermionic device being inclosed in an evacuated envelope.

Further objects and advantages of this invention will become apparent from a consideration of the following specificationtogether with the accompanying drawings in which:

Figure'l is a perspective View of a thermionic device embodying the invention, viewed from one end, i t

Figure 2 is a partially cut-away perspective view of the embodiment shown in Figure 1, viewed from the other end, with base removed,

Figure 3a is a schematic view of the control electrode in the off, or resting position,

Figure 3b is a schematic view of the control electrode in one operative position, whereby current flows in both anodes,

Figure 3c is a schematic view of the control electrode in another operative position, so that current flows in both anodes,

Figure 3d is a schematic view of the control electrode in the .full on position,

Figure 4a is a perspective view of a modified form of control electrode that may be utilized in my invention,

amended April 30, 1928; 370 O. G. 757) 2 Figure 4b is an end view of the modified form of control electrode illustrated in Figure 4a,

Figure 5a is a schematic View: of the modified form of control electrode in the off or resting position, i T.

Figure 5b is a schematic view of the'modified form of control electrode in position so that current flows in both anodes,

Figure 5c is a schematic View of the modified form of control electrode in such position that the direction of anode current is reversed.

Referring to Figures land 2 it isseenthat the reference numeral ll! refers to anevacuated en velope having a base H and contact prongs l2. A DArsonval typemeter 1'3 is. situated in end of the evacuated glass envelop Hi opposite from the base I. The DArsonva] meter i3 is of the conventional type having permanent magnet poles M, Hi, and a rectangular armature coil iii pivotally mounted in such fashionasto :perrnit rotation. The rotatable armature ,co-il it is mounted -on low-friction bearings (not shown) and is biased to zero position by the usual spring ll. i

A glass sealing stem 18 in the base of the tube supports a cylindrical cathode 1.9 of the in directly heated type. Two oppositely and prefera'bly symmetrically situated anodes Fill and 2! are supported by mounting rods 22 set in the sealing stem l8. A Ll-shaped control electrode or grid 23 made of a singl'e piece of heat-rasistant wire having two coplanar legs or prongs 2 4 and 25 is rigidly fastened at its lower end 28 to a meter armature shaft 2'! that is perpendicularly aimed to the meter armature coil. The control electrode 2 3 is formed and mounted in such fashion that thetwo sides or prongs 2t, 25 extend alongside the entire length of the cathode 19. The two prongs 2 and 25 are so situated that they are positioned 180 apart on a circleof which the-cathode l3 isthe center. i

The two. sides or prongs H, 25 of the control electrode 2 3rotate around the .outside of the cathode l9 when the armature coil E5 is moved by current flowing through it.

i As previously statedthe anode portion of the device is divided into two parts, 2i! and 2!, with each half electrically separate and situated diametrically opposite eachother and electronically surrounding about a third of the cathode It. The anodes -20 and 21 may be connected in parallel or any other manner desired.

It is thus seen that the application of an extremely weak current such as the output of a photoelectric cell or thermocouple to the armature coil |-6 will cause the coil and the control electrode 23 to rotate. The rotation of the control electrode 23 will cause a change in the amount of electron flow from the cathode I9 to the anodes 20 and 2|, with a resulting change in the anode current.

Referring to Figure 3a, there is disclosed in schematic fashion the normal resting or off position of the control grid 23. The control electrode or grid 23 is in such position that it prevents substantially any electrons from reaching either anode 20 or 2| with the result that no current flows in either anode circuit. The control electrode 23 should be biased with the proper potential to have a cut-off value when in this position.

In Figure 3b the control electrode has been moved slightly clockwise, the result being thatsome electrons which are not aifected by the grid reach the anodes 20 and 2| and cause a small current fiow in both anode sections.

In Figure 3c the control electrode or grid 23 has rotated still more in a clockwise direction with the result that a larger anode current will flow than in the previous illustrations. I

In Figure 3d the full on position is reache where the control electrode or grid 23 does not act on the sides of the cathode that face the anodes 20 and 2|, the result being that there is maximum current flow in both anode sections.

When no current is flowing through the meter 3, it is brought back to the "01T or normal position by the meter spring I! which swings the control electrode 23 between the cathode l9 and the anodes 20 and 2|, thus cutting off the current flow in the tube. The normal resting position of the control electrode 23 may 'be made such that current Will flow when no signal is applied by changing the position of the two anodes to a 90 setting from their original .position. changing the bias on the control electrode or grid the plate current can be made to vary in proportion. With a smaller bias the cut-off point would be reached more slowly than with a high one even with the same speed of control electrode movement. With a higher negative bias the cutoff position would be reached much quicker. The bias on the grid would also determine how far the control electrode 23 would have to be rotated by the meter to have a cut-off value, but the maximum distance in any case would be 90.

Referring to Figure 4, there is disclosed a modified type of control electrode or grid. The prongs or tines 24 and 25 are placed on the meter shaft 21 in such manner that the prongs are at an angle of 90 to each other, rather than 180 to each other as shown in Figures 1 and 2. With this arrangement, the anode currents will work in opposition to each other, that is, while the current in one anode is approaching a maximum value, the current in the other anode will 'be approaching a minimum value and vice versa. The modified control electrode, as illustrated in Figure 4, is shown in various operative positions in Figures a, 5b, and 50.

In Figure 5a, the control electrode or grid is shown in the normal resting or o position with the result that substantially all of the electrons emitted from the cathode flow to only the anode 20 with no current flowing in the other anode 2|.

In Figure 5b the control electrode or grid has been moved counter-clockwise with the result that part of the electron flow reaches each anode and a small amount of current flows in each anode circuit.

In Figure 5c the control electrode has been rotated still more in a counter-clockwise direction so that substantially all of the electron flow from the cathode is directed upon the anode 2| with no current flowing in the anode 20.

- Although I.have illustrated an embodiment of my invention in which two anodes are used, it is obvious that a tube of this type may be constructed with any number of anodes surrounding the cathode.

My electronic switch may be utilized in various ways. For example, relays may be placed in the anode circuits so that the extremely weak actuating currents fed into my device will operate them without utilizing any amplifying means. Or, the external anode circuits of my device may include any type of electrical indicating means that would not be capable of being directly operated by the extremely weak current available from a device such as a photoelectric cell or thermocouple.

Obviously the present invention is not restricted to the particular embodiments or uses shown herein and described, the scope of the invention being defined in the appended claims.

I claim:

1. An electrical switch comprising a sealed evacuated envelope inclosing a central cathode, a plurality of anodes radially spaced from said cathode, a fork-like control electrode having two parallel prongs, each prong extending lengthwise of said cathode, and electrical means positioned within said envelope for rotating said control electrode, said electrical means comprising a permanent magnet and a rotatable armature both coaxial with said cathode.

2. The structure according to claim 1 in which the two parallel prongs of said fork-like control electrode are positioned degrees apart on a circle concentric with said cathode.

3. An electrical switch comprising a sealed elongated evacuated envelope inclosing an elongated central coaxial cathode, a plurality of anodes radially spaced from said cathode, a forklike control electrode extending the length of said cathode and mounted for rotation between the cathode and anodes; and electrical means for rotating said control electrode positioned within said envelope including a permanent magnet and a rotatable armature, both coaxial with said cathode.

4. The structure according to claim 3 in which the two parallel prongs of said fork-like control electrode are positioned 90 apart on a circle concentric with said cathode.

BURNS CONLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,610,316 Quilter Dec. 14, 1926 2,155,419 Gunn Apr."25, 1939 2,221,744 Henry Nov. 1.2, 1940 2,225,032 Carbonara Dec. 1'7, 1940 2,315,176 Zacharia Mar. 30, 1943 FOREIGN PATENTS Number Country Date 480,491 Great Britain Feb. 23, 1938 

